N-acylamino-acids are useful in the pharmaceutical industry. Process for their racemisation are known; see Bull. Chem. Soc. Jpn. 60:649-652 (1987), 56:3744-3747 (1983), 60:4321-4323 (1987), 66:965-970 (1992), 66:2430-1437 (1992), and 64:191-195 (1991); and Agr. Biol. Chem. 43:395 (1979).
The known process generally require either specialised equipment or the use of reagents which are not applicable to industrial processes. For example, Hongo et al, Bull. Chem. Soc. Jpn. 54:3386 (1981), describe the use of chloroform and acetic anhydride for the racemisation of N-butanoyl-proline. This would clearly have a high environmental impact if carried out on a commercial scale.